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Hearthstone: Puzzle Lab Guide - Solutions and Answers Walkthrough

Our complete guide to beating the Puzzle Lab content in The Boomsday Project

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About Ed Thorn

Ed will not rest until a new Wario Land is announced.

Our Hearthstone Puzzle Lab guide contains a puzzle answers and solutions walkthrough for beating all of the content in the new mode.

A completely fresh Hearthstone meta is now well under way, and as well as introducing a whole host of new cards to the game, The Boomsday Project expansion has given us an exciting new single player adventure too.

It's completely unlike anything Blizzard's last two roguelike challenges where players would be tasked with battling through a series of boss encounters. Instead, the Puzzle Lab features more than 100 board-state challenges that you'll have to solve one by one.

The Puzzle Lab is split into four different challenge types, from completely clearing the board, to crafting a perfectly mirrored battlefield. Although some of the challenges present little difficulty at first, the difficulty swiftly ramps up once you start digging ever deeper into the missions.

In this third edition of our Puzzle Lab guide, we've put together solutions to help you complete every single puzzle. If there's a particular puzzle you just can't get your head around, we've got step by step instructions for getting them done and dusted in next to no time.


You can now use the links just a little further down the page to access complete walkthroughs for every single puzzle that exists in the Puzzle Lab. As a walkthrough, this guide is now complete!

Puzzle Lab Puzzle Types

As we've mentioned above, there are four puzzle variants to battle through in the Puzzle Lab. On top of this there's also a particularly tricky collection of puzzles set by Dr. Boom himself which we've included as a separate category down below.

Dr. Boom

These are by far the toughest puzzles you'll come across in the Puzzle Lab and you shouldn't feel bad if you have to dip into the spoiler territory we've prepared to help you get past them all!

- Dr. Boom Lethal Puzzle Solutions and Answers Walkthrough

- Dr. Boom Mirror Puzzle Solutions and Answers Walkthrough

- Dr. Boom Board Clear Puzzle Solutions and Answers Walkthrough

- Dr. Boom Survival Puzzle Solutions and Answers Walkthrough


These puzzles have one clear goal - deliver lethal damage against the opposing AI. With such a straightforward objective, it's a great starting point for all newcomers diving into the Puzzle Lab content.

- Poisonmaster Pollark Lethal Puzzle Solutions and Answers Walkthrough

- Myra Rotspring Lethal Puzzle Solutions and Answers Walkthrough

- Lil' Stormy Lethal Puzzle Solutions and Answers Walkthrough

- Electra Stormsurge Lethal Puzzle Solutions and Answers Walkthrough


For this puzzle type, you'll have to match the boss's side of the board exactly. There's no leeway so you'll have to copy both the minions' precise positions on the board as well as match their total health values. It's a totally different way of thinking about the game!

The end goal always chops and changes - do you try and heal the boss's minions to match you own, or eliminate them both by trading? The devs have stated that there are multiple solutions for most of these puzzles, with all sorts of avenues for you to explore.

- Test Subject Mirror Puzzle Solutions and Answers Walkthrough

- Astromancer Arwyn Mirror Puzzle Solutions and Answers Walkthrough

- Stargazer Luna Mirror Puzzle Solutions and Answers Walkthrough

- Zerek, Master Cloner Mirror Puzzle Solutions and Answers Walkthrough

Board Clear

To complete these challenges you'll have to clear the battlefield completely, and this includes having to wipe out your own minions in a single turn, while simultaneously blasting away your opponent's side of the board too.

This makes Deathrattle minions more challenging to toy around with. Defile was mentioned by the devs as an interesting mechanic that opens up many opportunities for this particular type of challenge.

- Dexter the Dendrologist Board Clear Puzzle Solutions and Answers Walkthrough

- Flobbidinous Floop Board Clear Puzzle Solutions and Answers Walkthrough

- Demonologist Draan Board Clear Puzzle Solutions and Answers Walkthrough

- Dr. Morrigan Board Clear Puzzle Solutions and Answers Walkthrough


For this puzzle type you'll need to hold out against the boss's special Hero Power. This'll require you to craft a very specific set play ahead of time, in order to buy yourself enough defensive power to survive the upcoming pain.

- Boomnician Breena Survival Puzzle Solutions and Answers Walkthrough

- Boommaster Flark Survival Puzzle Solutions and Answers Walkthrough

- Glow-Tron 2000 Survival Puzzle Solutions and Answers Walkthrough

- Crystalsmith Kangor Survival Puzzle Solutions and Answers Walkthrough

Puzzle Lab Overview

First of all, here's a quick overview of what to expect from Puzzle Lab when it goes live in Hearthstone.

  • The new content will be released on Tuesday 21st August, which is two weeks after the Boomsday set launched.
  • There are four different puzzle types in the Puzzle Lab: Lethal, Mirror, Board Clear and Survival.
  • The mode will feature unique cards and mechanics that are not available in the main game.
  • Unlike in the Adventure content of old, you'll be able to progress through the different lab types in any order you want. If you get stuck at any point, you can just dive into something else.
  • Puzzles are separated into groups of eight or nine, which minimises loading time and keeps the interface clean.
  • You'll be able to take a break from tackling these puzzle clusters, and then resume at a later time and exactly where you left off.
  • After successfully solving a puzzle, you'll seamlessly transition into the next one in the group, with a new hand and board state moving rapidly into place.
  • Puzzles only take place across one turn, so you don't have to spend too much time looking ahead, or thinking about where you might have gone wrong in previous turns.
  • Restarts are extremely quick, and you can reset the puzzle with a button press. This way if you know you've gone wrong, you can start all over again nice and quickly.

Head Scientists and Assistants

The Puzzle Lab is populated by a number of Head Scientists, each with their own Assistant. All of the Scientists - and some of the Assistants - already have a Hearthstone card associated with them, and so give us a flavour of what to expect when you encounter each one.

Here's a breakdown of who's who in the Puzzle Lab universe.

  • Crystalsmith Kangor (Head Scientist)
  • Glow-Tron 2000
  • Zerek, Master Cloner (Head Scientist)
  • Test Subject
  • Dr. Morrigan (Head Scientist)
  • Demonologist Draan
  • Electra Stormsurge (Head Scientist)
  • Lil' Stormy
  • Myra Rotspring (Head Scientist)
  • Poisonmaster Pollark
  • Stargazer Luna (Head Scientist)
  • Astromancer Arwyn
  • Boommaster Flark (Head Scientist)
  • Boomnician Breena
  • Flobbidinous Floop (Head Scientist)
  • Dexter the Dendrologist

Final Boss - Dr. Boom

The most difficult puzzles of all will see you facing off against Dr. Boom himself.

These challenges are expected to be incredibly challenging, but if you really get stuck then we've got all the answers tucked away on Metabomb (see the links above).

Puzzle Lab Rewards

Beat the Puzzle Lab content and you'll receive a special card back as your reward. Here's how it looks:

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  • Min123 #1 2 years ago
  • KanyeWezreal #2 2 years ago
    5-6 appears to have an issue. the solution refers to an emerald reaver but the actual card available is an emerald hive queen.
  • drunkbunny #3 3 years ago
    @Bedders 2-5 Dog Days (Morrigan) just to clarify
  • drunkbunny #4 3 years ago
    @Bedders Hi, solution 2-5 has a fatal flaw which is stopping me from completing it. Everything is fine up until the point where I need to finish off Golemagg and I understand that I need to leave Tundra until last, but if I send Timber Wolf into Golemagg just before Tundra, I lose the +1 attack buff and therefore I'm 1 attack short of finishing him off. I can see no other way of doing it - help!
  • warmonger123 #5 3 years ago
    The solution for 4-5 Poultry Provoked makes no sense. The only AOE I see is the Abomination for 2 damage that receives no buff; there’s no chain reaction, etc. how the hell does this work?
  • Bedders #6 3 years ago
    @Lofn Hi Lofn. I have no idea what's happened here. I've just put the solution in. Sorry about that!
  • Bedders #7 3 years ago
    @Betheldore Hi Betheldore. Using Power Shot on the middle minion reduces the cost of the minions either side of him. Be careful with the target you pick as he looks a lot like the Giants.

    I've tightened up the explanation a little bit to make the process clearer. Let me know if you're still having problems but this should be fine now.
  • Bedders #8 3 years ago
    @roadie-osd Hi Roadie. In the previous step you gave your hero Rockbiter Weapon. I'll make it clearer in the write-up.

    I'm just working through the other issues that have been raised and will have updates for you shortly.
  • roadie-osd #9 3 years ago

    Regarding puzzle 1-5 of "Airborn Assault", Step 5 of the puzzle instructions cant work. One cannot use the Shaman's hero to hit the remaining card, "River Crocolisk".

    With that being an impossibility, are there missing instructions for the shaman? it looks like this was written for a Druid to use their remaining hero power to wipe out the last card.

  • Betheldore #10 3 years ago
    2-5 Dog Days
    Cast Unleash the Hounds and then drop your Dire Wolf Alpha between two of them
    Timber Wolf now needs to be placed to the left of Tundra Rhino, with Scavenging Hyena located to the right
    Next, cast The Coin and then use Powershot on the AI's Golemagg minion
    Use two of your Unleash the Hounds puppies to kill one of the Molten Giants, and then send another hound with Dire Wolf Alpha into the remaining Giant
    Use your remaining minions to kill Golemagg

    But the Hounds only reach 3 attack with the above - how do you kill one 8/8 Giant with 6 attack? Help!
  • Lofn #11 3 years ago
    Full draw on lethal doesn't work as his life points are set at 30 so you can only take 10 off using that method and no other form of attack.

    Potion master pollark

    Please help as I am acing the mirror levels but am stuck here
  • NLB #12 3 years ago
    @ognyanbo93 you have to target the 1-1 elven archer with Power word shield, otherwise it won't work. Made the same mistake.
  • Bedders #13 3 years ago
    @ognyanbo93 I've just used the solution step by step to beat this again and it worked fine. Make sure you're following every last detail!
  • Bedders #14 3 years ago
    @Damphire5150 Just a quick update on 3-4 (Hello Darkness). I've just completed it twice without having to ping the Howlfiend so I've left it out rather than include it as an extra bit of busywork you need to do.
  • Bedders #15 3 years ago
    @ognyanbo93@Damphire5150 Hi folks, thanks for flagging these up and sorry you've had problems. The steps described were all used live in the game to complete the puzzles in question but it's most likely something's been lost in the rush to get written up.

    I'll go through these puzzles again and tidy up the walkthroughs. I hope you don't find any more but if you do please let me know so I can fix them straight away!


  • ognyanbo93 #16 3 years ago
    step 4-4 Full Northshire is not working
  • ognyanbo93 #17 3 years ago
    step 4-4 Full Northshire is not working
  • Damphire5150 #18 3 years ago
    Board Clear fixes:

    2-4 Plugging Away.
    The only step that's right here is Playing the Rhino, So do that.
    Then attack the middle Thermaplug with a hydra.
    Then use another hydra to attack the leftmost leper gnome,
    Then use your last active hydra to attack the gnome in the middle.
    Windfury a hydra, targeting the thermaplugg in the middle (he should have 1hp)
    Windfury the last hydra attacking the thermaplugg on the right (will kill it)
    Engineer to 1 of the gnomes, (spawning another one)
    Rhino to Thermaplugg, clean up the last two.
  • Damphire5150 #19 3 years ago
    @Damphire5150 Those are for the Mirror Lab ones btw.
  • Damphire5150 #20 3 years ago
    Puzzle 2-4 is missing this step: AFTER trading your Ice rager for the Loot horder, cast healing wave on the last Ultrasaur to kill it, then trade your Soulpriest with the Reckless rocketeer.

    Puzzle 3-4 is missing this step: FIRST MOVE, cast your hero power on howlfiend so it discards 1 of the cards in your opponents hand. Then follow the rest of the steps. by the time you hit the vanish step you will only put the 3 cards you need to pinch back from him.

    Just thought i should help.